When do you need to use two number lines to compare two fractions?

You need two number lines to compare two fractions when their denominators are different. The procedure is that you draw to segment lines of the same length but divede each line according to its denominator and then compare the place of the points that mark the fraction numbers, the line that content the marke further away from the start end will be indicate the greater fraction. For example, the fractions 3/4 and 7/10. One line will be divided inot 4 equidistant segments, and the other with 10 equidistant segments. The fraction 3/4 will be represented with 3 marks on the first line, and the fraction 7/10 will be represented with 7 marks on the second line. Now you can compare the size of the two segments marked adn decide which fraction is greater.